Why did Yakov finally remind Lavan how he had switched the wages ten times?
Ramban (Pasuk 36): Refer to 31:36:1:1*.
Seforno: He was telling Lavan that, it was not he (Yakov) who had stolen from him (Lavan), as Lavan had claimed (see Pesukim 26,30), but Lavan who had cheated him. 1
Ha'Emek Davar: Because you are a swindler, you suspect others (i.e. me). One who has a blemish, he accuses others of having that blemish! (Kidushin 70b)
Why did Yakov see fit to state here "Zeh loEsrim Shanah be'Veisecha ... " and "Zeh Esrim Shanah Anochi Imach" ... " (in Pasuk 38)?
Oznayim la'Torah: Based on the Seforno's explanation on Pasuk 24 (Refer to 31:24:2:2), he was telling Lavan that, bearing in mind his dedication during the fourtenn years that he worked for him (See Pesukim 39 & 40), he had no reason to do him harm; and bearing in mind that he had worked for fourteen years (seven of them under false pretences) and then six years during which time he (Lavan) had changed the conditions ten times, why on earth should he (Yakov) wish to return to him?